1、丰富常用的yum源及插件
CentOS-Base.repo(系统自带源)
epel源： yum install epel-release
elrepo源：rpm --import https://www.elrepo.org/RPM-GPG-KEY-elrepo.org
rpm -Uvh http://www.elrepo.org/elrepo-release-7.0-2.el7.elrepo.noarch.rpm
nux-dextop源: 先下载 https://copr.fedoraproject.org/coprs/librehat/shadowsocks/ 下载比较慢，多试几次之后就好了。
安装：rpm -ivh nux-dextop-release-0-1.el7.nux.noarch.rpm
2、.安装cairo-dock栏
Mac系统的dock栏是不是很惊艳，linux下也有类似应用( ^ω^)
此应用需要nux-desktop源支持，所以如果之前的yum源都配上了，那下面就很简单了，一句命令搞定：yum install cairo-dock
执行yum install cairo-dock 经常提示No package cariro-dock available 多试几次就好了，和网络有关系
到最后的时候报错
Transaction check error:
file /usr/lib/systemd/system/blk-availability.service from install of device-mapper-7:1.02.107-5.el7.x86_64 conflicts with file from package lvm2-7:2.02.105-14.el7.x86_64
file /usr/sbin/blkdeactivate from install of device-mapper-7:1.02.107-5.el7.x86_64 conflicts with file from package lvm2-7:2.02.105-14.el7.x86_64
file /usr/share/man/man8/blkdeactivate.8.gz from install of device-mapper-7:1.02.107-5.el7.x86_64 conflicts with file from package lvm2-7:2.02.105-14.el7.x86_64
Error Summary
于是下载安装rpm -ivh lvm2-2.02.115-3.el7.src.rpm
结果提示：
Updating / installing...
1:lvm2-7:2.02.115-3.el7 ################################# [100%]
warning: user mockbuild does not exist - using root
warning: group mockbuild does not exist - using root
warning: user mockbuild does not exist - using root
warning: group mockbuild does not exist - using root
warning: user mockbuild does not exist - using root
warning: group mockbuild does not exist - using root
warning: user mockbuild does not exist - using root
warning: group mockbuild does not exist - using root
warning: user mockbuild does not exist - using root
warning: group mockbuild does not exist - using root
warning: user mockbuild does not exist - using root
warning: group mockbuild does not exist - using root
warning: user mockbuild does not exist - using root
warning: group mockbuild does not exist - using root
warning: user mockbuild does not exist - using root
warning: group mockbuild does not exist - using root
新建立个组
#groupadd mockbuild
#useradd mockbuild -g mockbuild
还是报之前的错。
于是yum upgrade 之前做过一次系统更新，结果导致系统直接启动不起来。悲催的只好重装了系统。因此要注意upgrade和update的区别
注意 yum update 和 yum upgrade的区别
yum -y update
升级所有包，改变软件设置和系统设置,系统版本内核都升级
yum -y upgrade
升级所有包，不改变软件设置和系统设置，系统版本升级，内核不改变
upgrade 执行后有1641个包要更新，漫长的等待
Updating : libnm-gtk-1.0.6-2.el7.x86_64 586/1641
Updating : libgdata-0.17.1-1.el7.x86_64 587/1641
Updating : evince-libs-3.14.2-5.el7.x86_64 588/1641
Updating : gjs-1.42.0-1.el7.x86_64 589/1641
Updating : evolution-data-server-3.12.11-24.el7.x86_64 590/1641
Updating : libreport-gtk-2.1.11-32.el7.centos.x86_64 591/1641
Updating : libpeas-1.12.1-1.el7.x86_64 592/1641
Updating : zenity-3.8.0-5.el7.x86_64 593/1641
Updating : gtksourceview3-3.14.3-1.el7.x86_64 594/1641
Installing : vte291-0.38.3-2.el7.x86_64 595/1641
.。。。。。。。。。
upgrade之前
[root@gxcc soft]# uname -r
3.10.0-123.el7.x86_64
upgrade 之后 重启，启动界面会多一个启动内核。
再次安装cairo-dock 就一切顺利了。
自此dock也出现了。